Jefferson is a census-designated place (CDP) in Jefferson Parish, Louisiana, United States, on the north side (referred to as the “East Bank”) of the Mississippi River. Jefferson is allocation of the New Orleans–Metairie–Kenner metropolitan statistical area. The population was 11,193 at the 2010 census, and 10,533 in 2020. It is often known by locals as “Old Jefferson” (to distinguish itself from the stop of Jefferson Parish), but should not be confused with Old Jefferson in East Baton Rouge Parish, Louisiana.

Early French colonial documents show what would become Jefferson as ration of the “Tchoupitoulas Coast” of Native American settlement. In the French and Spanish colonial epoch it was separated into a series of plantations in the same way as boundary lines perpendicular to the Mississippi River.

In the American Civil War, Camp Parapet was built originally by Confederate forces to defend New Orleans from an attack from the upriver side. After the Union liberated the city sailing occurring from downriver, U.S. troops expanded the fortifications to defend from Confederate counterattacks which never came.

What is now Jefferson includes formerly separate small communities dating incite to the 19th century, including, Hoeyville, New Carrollon, Southport, and Shrewsbury, along bearing in mind 20th century subdivisions/land developments including Azalea Gardens, Camellia Gardens, Jefferson Heights, and Rio Vista. Some of these names continue to sometimes be used locally to deal with to neighborhoods.^{[citation needed]}